Early this week, State Department spokeswoman Victoria Nuland said the administration was not going to assign grades to the agreement until it learned more, but said that “questions of Palestinian reconciliation are an internal matter for Palestinians.”

On Thursday, Nuland said the administration was still “waiting to see whether – how this deal might be implemented if, in fact, it is implemented at all.”

“What matters to us – and what matters, we think, to the process that we are trying to keep on track here – is that Abbas remains the president, that [Salam] Fayyad remains the prime minister,” she added.

Yet the principal element of the deal signed by Abbas and Hamas leader Khaled Meshaal in Doha, Qatar, on Monday has Abbas replacing Fayyad as Palestinian Authority (P.A.) prime minister, while also holding onto his current position as P.A. president.

In fact, Hamas’ unwavering rejection of Fayyad retaining the prime minister’s post has stymied several previous attempts at Fatah-Hamas reconciliation. Fayyad, a U.S.-trained economist, is highly regarded in Western capitals but has never won the Islamist group’s acceptance.

Hamas seized control of the Gaza Strip amid bloody fighting in 2007, since when the jurisdiction of the Fatah-dominated P.A. has been restricted to the West Bank. Attempts to mediate reconciliation between the rival factions have been led for years by the governments of Egypt and, more recently, Qatar.

Hamas’ participation in a P.A. government should put future American financial aid at risk, according to U.S. law.

The U.S. has provided the P.A. with more than $3.5 billion in bilateral assistance since the Oslo peace accords launched Palestinian self-rule in the mid-1990s.

Under the 2006 Palestinian Anti-Terrorism Act (PATA), assistance to the P.A. is conditioned on its compliance with obligations to renounce and combat violence, recognize Israel’s right to exist, and abide by existing agreements signed with Israel.

Those same requirements are the criteria established by the Mideast “Quartet” – the U.S., Russia, European Union and the U.N. – for Hamas to participate in the political process.

Nuland on several occasions this week reiterated the Quartet criteria.

“As we’ve said again and again and again with regard to Hamas, any Hamas participants who come into the government, if they want to work with us, have to recognize the state of Israel, have to renounce violence, and have to agree to uphold any past agreements of the P.A.,” she said Thursday. “That standard does not change.”

According to a Congressional Research Service report (CRS) report updated in January 2011, legal conditions and restrictions on U.S. aid to the P.A. include a ban on aid “for Hamas or Hamas-controlled entities.”

Under PATA, the report says, no aid is permitted for a power-sharing government that includes Hamas unless the president certifies that the government and all of its ministers accept “(1) recognition of ‘the Jewish state of Israel’s right to exist’ and (2) acceptance of previous Israeli-Palestinian agreements.”

Under certain conditions, including consultation with appropriate congressional committees, the president may waive, for national security purposes, restrictions on aid for the P.A. president and judiciary, if they are not Hamas-controlled, the CRS report says.

Israeli Prime Minister Binyamin Netanyahu said this week Abbas had to make a choice between negotiating a peace settlement with Israel or reconciling with “an Iranian-backed terror organization committed to Israel’s destruction.”

“P.A. President Abbas cannot have it both ways, either he has a pact with Hamas or he has peace with Israel,” the Israeli foreign ministry said in a paper Wednesday. “If he implements the Doha agreement and joins forces with the enemies of peace, the P.A. would be abandoning the path of reconciliation with Israel.

“Israel hopes that the Palestinian Authority will chose peace,” the paper continued. “In recent weeks, Israel and elements in the international community have made great efforts to advance that goal. It would be a terrible shame if the P.A. were to unite with the forces of terrorism, turning its back on the negotiating process which is the only means to achieving the peace that is Israel's greatest dream.”